MAX1687/MAX1688
Step-Up DC-DC Converters with
Precise, Adaptive Current Limit for GSM
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS
(V
IN
= V
ON
= +3V, V
LIM
= 1V (MAX1687), V
CHG
= 1V (MAX1688), V
FB
= 1.5V, V
OUT
= 6V, T
A
= -40°C to +85°C, unless otherwise noted.)
(Note 1)
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
V
LIM
= V
CHG
= 1V
V
LIM
= V
CHG
= 0.65V
I
IN
IN rising, 1% hysteresis
V
FB
= 1.125V, V
OUT
= 3V (MAX1688)
FB rising, 2% hysteresis
I
REF
= 0 to 10µA
V
FB
= 1.5V
Shutdown V
IN
= 4.2V, LX2 connected to LX1,
V
OUT
= 0, ON = GND
V
LIM
= V
CHG
= 1V
CONDITIONS
mA
145 240
I
RIPPLE
Ripple Current
A
0.44 0.57
I
PEAK
Ω
0.18
R
SENSE
Sense Resistor
0.73 0.90
Peak Current
V
2.35 2.65
V
2.7 6
Input Voltage Range
Input Undervoltage Lockout
mmho
0.16 0.24
gm
FB
FB Transconductance
V
1.20 1.30
FB Set Voltage
V1.212 1.288V
REF
Reference Voltage
ms
0.6 2
T
DELAY
Shutdown Delay
mA
5
I
SHDN
Input Supply Current
µA10
UNITSMIN TYP MAXSYMBOLPARAMETER
V
IN
= 4V, V
FB
= 0, V
OUT
= 0
V
IN
= 2.7V
V
IN
= 2.7V
Ω
70
Precharge On-Resistance
Ω
0.7
Ω
0.8
N-Channel On-Resistance
P-Channel On-Resistance
Typical Operating Characteristics
(V
IN
= +3.3V, V
OUT
= 5V, V
LIM
= 1V, Figures 6b and 7, T
A
= +25°C, unless otherwise noted.)
Commentaires sur ces manuels